CN115175594A

CN115175594A - Systems and methods for wearable atmospheric vapor extraction

Info

Publication number: CN115175594A
Application number: CN202180011059.9A
Authority: CN
Inventors: C.弗里森; K.萨卢姆; M.罗宾逊
Original assignee: Global Source Co
Current assignee: Global Source Co
Priority date: 2020-01-27
Filing date: 2021-01-26
Publication date: 2022-10-11
Also published as: US20230078132A1; EP4096476A1; WO2021154739A1; AU2021214933A1; EP4096476A4

Abstract

Systems and methods related to wearable atmospheric water generation devices are described herein. The system may include a sorbent material within a sorbent chamber configured to capture water vapor from ambient air and may be configured to create a reduced pressure condition within the sorbent chamber, thereby desorbing water from the sorbent material. The system may further comprise a condenser for producing liquid water from the desorbed water vapour.

Description

Systems and methods for wearable atmospheric vapor extraction

Cross Reference to Related Applications

This application claims benefit of U.S. provisional patent application No.62/966,491, filed on 27.1.2020/2020, entitled SYSTEMS AND METHODS FOR wear adjustable ATMOSPHERIC VAPOR EXTRACTION, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates to wearable, portable, stand-alone, and/or miniature systems and methods for generating or extracting liquid water from ambient air.

Background

Producing liquid water by extracting water vapor from ambient or atmospheric air can present various challenges. Certain challenges include those associated with maximizing water production rate (production rate) and/or efficiency at low cost and high reliability.

The water generation system can convert the latent heat of condensation (approximately ah at ambient conditions) of water _vap =660 Wh/kg) from its vapour phase transfer to condense gas. Conventional water generator solutions are typically grid-tied systems including conventional dehumidification cycles (e.g., direct refrigeration and condensation of atmospheric water vapor). A subset of these systems may include a conventional liquid drying circuit, the purpose of which is to extend the humidity range of the refrigeration circuit in order to extract more water vapor. In conventional atmospheric water generators employing direct cooling of ambient air via direct refrigeration and condensation, the amount of energy input may be reduced via utilization of a refrigerant as a working fluid in a closed loop cycle (e.g., vapor compression). However, the ratio of condensation (condensation) heat to energy input, coefficient of performance (COP), can vary by orders of magnitude over the range of potential field deployment environments (e.g., based on the relative humidity of these environments). For typical refrigerants (e.g., typically characterized by on the order of 40 Wh/kg), a closed thermodynamic loop incurs energy costs that may not be suitable for the stringent operating, size, weight, and power requirements of wearable or portable devices.

In addition, conventional water generating devices typically have a large footprint (e.g., 25 to 200 square feet). The size and complexity of such conventional water generator systems may stem from the need to handle multiple air stream and liquid desiccant circuits, as well as heat exchange mechanisms and containment (isolation) solutions. Such complexity may require the aforementioned footprint and result in various inefficiencies associated with power management of system subcomponents.

In addition, conventional liquid desiccants may exhibit slow adsorption kinetics and isotherms that lose efficacy below moderate RH values. While high humidity and high ambient temperature conditions can result in performance of these large systems being less than 300Wh/L, performance can extend to 1500Wh/L under more average conditions and up to 5000Wh/L under drought (arid) conditions. Without being bound by any particular theory, the basic thermodynamics of conventional water generator systems can result in poor performance (i.e., lower water production efficiency) under moderate or poor conditions, thereby greatly limiting their efficacy and applicability.

Accordingly, there is a need for wearable, stand-alone, compact, portable, and/or field-deployable systems and methods for producing liquid water from ambient or atmospheric air using inexpensive and reliable methods that maximize water production rates and/or efficiencies.

Disclosure of Invention

A wearable water generating device is provided herein. The wearable water generating device may include: a sorbent chamber comprising a sorbent material to capture water vapor from ambient air during a loading cycle, the sorbent material configured to absorb thermal energy; a vacuum pump configured to create a reduced pressure condition within the adsorbent chamber, thereby desorbing water from the adsorbent material during a release cycle, wherein the reduced pressure condition increases a ratio of a vapor pressure of water captured by the adsorbent material to a partial pressure of water vapor in the adsorbent chamber; and a condenser (condenser) for generating liquid water from the desorbed water vapor received from the vacuum pump.

In various embodiments, the sorbent material is configured to absorb thermal energy from a wearer of the atmospheric water generating device. In various embodiments, the sorbent material is configured to absorb thermal energy from solar radiation impinging on the atmospheric water generating device. In various embodiments, the wearable water-generating device further comprises a fan configured to cool the condenser. In various embodiments, the vacuum pump discharges the desorbed water vapor as a vapor at atmospheric pressure. In various embodiments, a vacuum pump evacuates the desorbed water vapor to a pressure higher than atmospheric pressure.

In various embodiments, the wearable water-generating device further comprises a compressor in combination with a vacuum pump, and the desorbed water vapor is vented from the sorbent chamber to a pressure greater than atmospheric pressure. In various embodiments, the wearable water generating device is configured to operate in an open loop thermodynamic cycle. In various embodiments, the outlet of the vacuum pump is configured to exchange heat from water vapor discharged therefrom to the adsorbent chamber, thereby increasing at least one of the rate and vapor pressure of water vapor desorbed from the adsorbent material.

In various embodiments, the sorbent material comprises an ionic liquid. In various embodiments, the adsorbent material comprises a solvent-less ionic liquid epoxy resin. In various embodiments, the sorbent material comprises an ionic liquid entrained in a porous solid. In various embodiments, the sorbent material comprises a metal-organic framework. In various embodiments, the wearable water generating device is configured to exchange heat from the vacuum pump to the sorbent material. In various embodiments, the wearable water generating device is configured to exchange heat from the condenser to the sorbent material such that the power requirements of the vacuum pump are reduced, thereby increasing the coefficient of performance. In various embodiments, the sorbent chamber includes an inlet for input of a gas leak during a release cycle. In various embodiments, the carrier gas leak comprises ambient air.

In various embodiments, the wearable water-generating device further comprises one or more sensors, and a controller coupled to the one or more sensors and the vacuum pump, the controller configured to maximize the water-generation rate in the condenser by adjusting the reduced-pressure condition during the release time. In various embodiments, the wearable water generating device further comprises a controller configured to maximize the water production rate of the condenser by maintaining the reduced pressure condition in the sorbent chamber below a predetermined set point. In various embodiments, the controller maintains the reduced pressure condition in the adsorbent chamber below a predetermined set point by adjusting the power input to the vacuum pump. In various embodiments, the controller is further configured to adjust the flow rate of the gas leak to maintain a reduced pressure condition in the sorbent chamber.

In various embodiments, provided herein is a method for operating a wearable water generating device. In various embodiments, the method comprises: the method includes capturing water vapor from ambient air by a sorbent material in a sorbent chamber during a loading cycle, creating a reduced pressure condition in the sorbent chamber during a release cycle, desorbing water from the sorbent material during the release cycle, and condensing water vapor output from the sorbent chamber into liquid water during the release cycle.

In various embodiments, the loading cycle and the release cycle operate in an open loop thermodynamic cycle. In various embodiments, the method further comprises inputting the gas leak into the sorbent chamber during a release cycle. In various embodiments, capturing water vapor includes inputting ambient air into a sorbent chamber of a wearable water generating device. In various embodiments, desorbing water from the sorbent material during a desorption cycle includes exposing the sorbent material to a low grade (grade) heat source. In various embodiments, the low grade heat source comprises thermal energy from the wearer of the atmospheric water generating device. In various embodiments, the low grade heat source comprises passive ambient heat, solar energy, or a combination thereof.

In various embodiments, creating reduced pressure conditions comprises adjusting the reduced pressure conditions by adjusting a vacuum pump rate. In various embodiments, creating the reduced pressure condition comprises adjusting the reduced pressure condition by adjusting a flow rate of the carrier gas into the adsorbent chamber.

In various embodiments, the method further comprises: determining a physical condition of the wearer; and adjusting the reduced pressure condition based on the determined physical condition. In various embodiments, the physical condition of the wearer is body heat, temperature, metabolic rate, or a combination thereof of the wearer. In various embodiments, the method further includes determining that the wearer's physical condition has increased above a predetermined threshold, and reducing the amount of energy input to create the reduced pressure condition based on the determined wearer's physical condition. In various embodiments, the method further comprises determining that the wearer's physical condition has decreased below a predetermined threshold, and decreasing the pressure within the adsorbent chamber based on the determined wearer's physical condition. In various embodiments, the method further comprises: determining an amount of water in the sorbent material; and in response, determining a sorbent chamber pressure set point based on the determined amount of water.

The foregoing features and elements may be combined in various combinations without exclusion unless explicitly stated otherwise herein. These features and elements (elements) and operation of the disclosed embodiments will become more apparent from the following description and drawings.

Drawings

The following drawings are illustrative in nature and not restrictive. For purposes of brevity and clarity, each feature of a given structure is not always labeled in every figure in which that structure appears. Like reference numerals do not necessarily denote like structures. Conversely, the same reference numerals may be used to denote similar features or features having similar functions, and different reference numerals may be used. The views in the drawings are drawn to scale (unless otherwise noted) which means that the dimensions of the depicted elements (components) are accurate relative to each other for at least the embodiments in the views.

Fig. 1 depicts a vapor cycle on a water vapor p-h diagram according to one embodiment, comprising state (1) the adsorbed vapor on the adsorbent material is subjected to a reduced atmospheric pressure via a vacuum pump, driving a vapor pressure gradient and desorbing the water vapor; a pump outlet for water vapour generated from the adsorbent material in state (2) (e.g. at least partially vapour at atmospheric conditions), which is then cooled to a liquid phase (3) by a condenser, and continuously rejecting heat to ambient conditions (4);

fig. 2 depicts the water vapor pressure on the adsorbent material at an equilibrium Relative Humidity (RH) level (solid line) compared to the vacuum chamber pressure applied by the pump (P _ c), both as a function of material/chamber temperature, according to one embodiment;

FIG. 3 depicts an Atmospheric Water Extractor (AWE) and cyclic operating scheme according to one embodiment;

FIG. 4 depicts an Atmospheric Water Extractor (AWE) and cyclic operating scheme according to one embodiment;

FIG. 5 depicts enthalpy work and water mass absorption within the range of 10-100% RH for three representative categories of sorbent materials according to one embodiment: conventional silica gels (Si-gels), metal Organic Frameworks (MOFs) and Ionic Liquids (ILs);

fig. 6 shows a simplified sier (or solventless (low solvent) ionic liquid epoxy) polymerization reaction according to one embodiment, where both components are ionic liquids;

fig. 7 (a) and 7 (b) illustrate an exemplary silicon structure according to one embodiment;

fig. 8 (a) and 8 (b) show exemplary ionic liquid structures. Figure 8 (a) shows a tetraamino aromatic crosslinker with bromide counter ion and figure 8 (b) shows a diepoxide imidazolium dodecyl sulfate, according to one embodiment;

fig. 9 (a) and 9 (b) are images of the synthesized sil polymer formed with an integral hierarchical pore former (integral hierarchical pore former) in fig. 9 (a), and a photomicrograph of the same sil polymer in fig. 9 (b), according to one embodiment;

FIG. 10 is a graph of water absorption mass% over a range of Relative Humidity (RH)% for four SILER-based ionomer polymer systems according to one embodiment; and

fig. 11 depicts a flowchart of an exemplary method according to one embodiment.

Detailed Description

The present disclosure includes embodiments of wearable, portable, stand-alone, compact, and/or field-deployable systems and methods (e.g., for generating liquid water from air). The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically. The terms "a" and "an" are defined as one or more unless the disclosure clearly requires otherwise. The term "substantially" is defined as largely, but not necessarily wholly, as understood by one of ordinary skill in the art (and including designations; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel). In any disclosed embodiment, the terms "substantially" and "about" may be substituted with the stated "within". Said percentages, "wherein said percentages include 0.1, 1, 5, and 10%. Further, a device or system configured in a certain way is configured in at least that way, but may also be configured in ways other than those specifically described.

The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "has"), "include" (and any form of include, such as "includes" and "includes)") and "contain" (and any form of contain, such as "contains" and "contains)") are open-ended linking verbs. As a result, a device that "comprises," "has," "includes" or "contains" one or more elements (components) possesses those one or more elements (components), but is not limited to possessing only those elements (components), as well as a method that "comprises," "has," "includes" or "contains" one or more operations or steps possesses those one or more operations or steps, but is not limited to possessing only those one or more operations or steps.

As used in this disclosure, the terms "adsorption", "absorption", and the like are interchangeable. While absorption is generally understood to be a bulk (bulk) phenomenon and adsorption is a surface-based phenomenon, the hygroscopic materials, desiccants, and/or adsorbent media of the present disclosure can capture water vapor by adsorption, absorption, or a combination thereof.

Any embodiment of any of the apparatus, systems, and methods may consist of, or consist essentially of (but not include/contain/have) the described steps, elements (components), and/or features. Thus, in any claim, the term "consisting of … …" or "consisting essentially of … …" may be substituted for any of the open-linked verbs listed above to alter the scope of a given claim, rather than use the scope of the open-linked verbs. One or more features of one embodiment may be applied to other embodiments or implementations, even if not described or illustrated, unless expressly prohibited by the nature of the disclosure or the embodiments.

A wearable, portable, stand-alone, and/or small device for efficient atmospheric water extraction or generation is described herein. In one example, the wearable water-generating device can support the total water demand of an individual person or wearer (e.g., a warrior on a battlefield). Described herein are combinations of advanced sorbent materials, system operating methods, thermodynamic cycles, and other features that can be integrated into field deployable devices. As used herein, a wearable atmospheric water generation device refers to a water generation device that may be wearable, portable, stand-alone, small, and/or deployable in the field; reference to one of these features should not be understood as excluding the other features.

The wearable water-generating device may utilize ultra-low grade heat (or low temperature, e.g., <60 ℃ or <40 ℃) sources, such as ambient heat, body heat, and/or solar energy, for efficient production of liquid water from air, enabling small and/or wearable devices to produce individual or personal quantities of water under harsh environmental conditions (e.g., low ambient relative humidity) and/or without or with available external power sources. By integrating different sorbent material systems, controlled thermodynamic cycles, and/or embedded software and controls, the wearable water generation device can use lower grade heat from an external source for full off-grid (off-grid) applications.

The wearable water-generating device can be configured to function by cycling the sorbent material described herein between atmospheric pressure conditions and low pressure or reduced pressure conditions. The sorbent material of the wearable water-generating devices described herein can adsorb water vapor at as low as 3% or 10% rh, can have little or no vapor pressure by itself, can have high thermal conductivity, and can be minimally susceptible to adsorption site poisoning from atmospheric constituents. The wearable water generating device itself may comprise a high efficiency and/or small vacuum pump which may achieve a lower pressure than the vapour pressure of water adsorbed and/or absorbed into the hygroscopic or absorbent material of the device.

The high efficiency wearable water generation devices, systems, and methods described herein and their related features represent a different approach to enabling a new paradigm of infrastructure-less drinking water production from air. In various embodiments, the functional surface area of the hygroscopic, adsorbent, or desiccant material for the wearable water-generating device, for water absorption and heat exchange purposes, is designed and configured to operate within a small volume water production range (e.g., within a range of 1.5L) of the individual wearer. In various embodiments, one or more sorbent materials and/or thermodynamic cycles are defined for very low grade heat sources (e.g., heat from the human body, less than about 40 ℃, passive environmental heating and/or solar radiation impinging on the device, etc.), which may be used for water vapor desorption. In various embodiments, by applying vacuum and/or controlled reduced pressure conditions during the desorption phase of the water generation cycle, the temperature at which water vapor is extracted can be reduced and the efficiency of the apparatus can be increased.

In various embodiments, a particular set of sorbent materials, their production or assembly, and defined thermodynamic cycles are integrated into a field deployable or wearable water generation device. For ease of description, the following first describes the thermal cycle that enables the desired energy conversion rate, and then describes the desired sorbent material properties, thereby introducing integrated sorbent material features.

Wearable water generation device operation or thermodynamic cycle

The various wearable water generation devices described herein provide an embodiment of an open loop thermodynamic cycle that employs water vapor as a working gas for atmospheric water extraction. The various wearable water generation devices described herein may be particularly suitable for wearable, field-deployable, or remote applications. For ease of description, the operating cycle is first introduced to clarify the basis for incorporating possible sorbent materials to enable operation over a wide range of environmental conditions.

The wearable water generation devices and methods described herein may be implemented as an open-loop thermodynamic cycle that employs water as a working fluid, thereby significantly increasing the coefficient of performance (COP) for water vapor extraction from ambient air. According to one embodiment, fig. 1 illustrates an exemplary open-loop vapor cycle on a pressure-enthalpy diagram, wherein the complete open-loop cycle (represented by the thick black line) from state 4 to 1 is not directly connected (i.e., open-loop cycle). In various embodiments, the wearable water-generating device can be configured to continuously reject heat to ambient conditions during hydrolytic inhalation, rather than reintroducing heat into a sorbent material disposed in a sorbent chamber of the wearable water-generating device. The sorbent material may first be exposed to ambient air as a source of water communicated into the wearable water-generating device. Then, in state 1, the moisture-laden sorbent material can be placed under reduced atmospheric (e.g., less than 1 atm) conditions to reduce the partial pressure of water vapor on the sorbent material. In various embodiments, the wearable water-generating device, e.g., via a controller (e.g., PCB, wireless, etc.), can maintain the pressure of the internal system (e.g., adsorbent-containing chamber) below a set point based on the properties of the adsorbent material and/or the one or more available low-grade heat sources. For example, in various embodiments, the controller may determine whether the temperature of the wearer of the wearable water-generating device is above a predetermined threshold, below a predetermined threshold, or between predetermined thresholds (e.g., between 35-40 ℃), and in response, maintain the pressure in the sorbent chamber below a predetermined threshold or between predetermined thresholds (e.g., less than 1atm, less than about 0.8atm, between 0.1 and 0.8atm, etc.).

In various embodiments, the driving force J of vapor desorption (e.g., from the adsorbent material in the adsorbent chamber of the wearable water-generating device) and the equilibrium vapor pressure P of water on the adsorbent material _v And water in the atmosphere surrounding the device sorbent material (e.g., within a sorbent chamber of a wearable water-generating device)Partial pressure P of steam _p The difference between them is proportional as shown in equation (1).

J～P _v (T)-P _p (1)

In accordance with equation (1), P _v Increases with increasing heat flux and/or temperature applied to the sorbent material (e.g., via heat transfer from the wearer's body to the sorbent material), while P increases _p As the atmospheric pressure decreases (e.g., in the sorbent chamber of the wearable water generating device). In various embodiments, the heat flux and/or atmospheric pressure in the sorbent chamber of the wearable water-generating device may be further controlled (e.g., via a controller) by the wearable water-generating device to drive the value of J that facilitates vapor desorption. In various embodiments, the controller may determine whether the body heat, temperature, and/or metabolic rate of the wearer has increased above a predetermined threshold, and in response, reduce the amount of energy (e.g., from an on-board device battery) directed to the on-board pumping device to reduce the pressure within the sorbent chamber. In various embodiments, the controller may determine that the body heat, temperature, or metabolic rate of the wearer has decreased below a predetermined threshold, and in response, activate the on-board pumping device to decrease the pressure within the sorbent chamber. In various embodiments, the controller may determine, estimate, and/or track the amount of water (amount) or quantity (quality) retained by the adsorbent material (e.g., via a conservation of desorption-absorption mass calculation based on known adsorbent material properties and pressure and/or temperature), and in response, determine an adsorbent chamber pressure set point; for example, in various embodiments, the controller may decrease the chamber pressure in response to a decrease in the body heat and/or temperature of the wearer, and/or increase the chamber pressure in response to an increase in the body heat, body temperature, etc. of the wearer.

By way of illustration, fig. 2 depicts the gradient between the equivalent vapor pressure on the adsorbent material (in solid lines under different RH loading conditions) and the adsorbent chamber pressure P _ c (where the partial pressure of water vapor in the chamber is a fraction thereof) represented by the dashed line. As shown in FIG. 2, at less than about 20% RH, the adsorbent chamber vacuum can generate the driving force for water desorption (as shown by the difference between the 20% RH curve and the 15kPa adsorbent chamber pressure curve). In various embodiments, any low heat flux level (e.g., low temperature heat source from the wearer's body) increases this driving force for hydrolytic absorption. As will be described in greater detail below, in various embodiments, the controller can determine an operational set point for driving desorption of water vapor (and thus generation of water) by controlling the difference between the equivalent vapor pressure of the sorbent material in the sorbent chamber and the sorbent chamber pressure.

In various embodiments, the desorbed vapor may be compressed back to atmospheric pressure or above via a vacuum pump operably coupled to the wearable water-generating device and/or configured as a component of the wearable water-generating device. In some embodiments, the wearable water generating device may comprise a compressor unit downstream of the vacuum pump and/or before the condenser. In various embodiments, the output of the pump may be saturated and/or supersaturated steam, which is then cooled to a water saturation line via a condenser. Consistent with fig. 2, in various embodiments, the COP of an open-loop cycle as described herein may be about 9 (where "about" means +/-2), such that one liter of water may be produced via 73Wh energy input, and correspondingly greater than 5 liters of water over a 24 hour period using 400 Wh. In various embodiments, additional energy input to adjust the equivalent vapor pressure of the material in equation (1) may help further improve COP. For example, heat exchange from the condenser to the adsorbent material may reduce the pump demand (pump demand) from about 30kPa to about 45kPa, thereby increasing the COP to about 11.

Fig. 3 illustrates a wearable water-generating device 100 and an exemplary cycling protocol (shown by arrows) according to various embodiments. Wearable water generation device 100 may include a device housing 102 coupled to or worn by individual 150, an adsorbent chamber 110 containing an adsorbent material 112, a vacuum pump or pressure reduction assembly 120 operably coupled to adsorbent chamber 110, a fan or blower 130, and/or a condenser 140. The components and features of fig. 3 are not drawn to scale, but are shown for ease of description. In various embodiments, sorbent chamber 110 may be sealable via valves and/or other mechanisms activated during a release cycle of wearable water generating device 100. The vacuum pump 120 can be configured to desorb the vapor from the adsorbent chamber 110 and compress it to atmospheric pressure (e.g., steam or at least a portion of steam), as shown from cycle portion 1 to cycle portion 2. In some embodiments, the fan 130 cools the condenser 140 to improve the condensation and/or generation of liquid water, as shown from the circulation portion 2 to the circulation portion 3. At the adsorbent chamber 110, the adsorbed vapor may undergo the open loop thermodynamic cycle described above and with respect to fig. 1. In various embodiments, an open-loop thermodynamic cycle may be controlled for the production of liquid water, such as controller 104 described herein.

Fig. 4 illustrates a wearable water-generating device 100 and an exemplary cycling protocol (shown by arrows) according to various embodiments. In various embodiments, sorbent chamber 110 can be placed under vacuum or negative pressure (e.g., via vacuum pump 120). In various embodiments, a gas leak 160 (e.g., ambient air input to sorbent chamber 110 via a valve) may be introduced into the interior volume of sorbent chamber 110. The numerical indicators used to refer to components in fig. 4 are similar to the numerical indicators used to refer to components or features in fig. 3 above, and while some components may not be depicted in fig. 4 for ease of description, some or all may be present in the system of fig. 4 in various embodiments. In some embodiments, the gas leak 160 may be heated by any desired heating mechanism or source (e.g., via low-level body heat of the wearer 150) prior to and/or during input to the sorbent chamber 110. In some embodiments, heat may be transferred from the expanded water vapor output of sorbent chamber 110 indicated at cycle portion 1at or above atmospheric pressure to gas leak 160 entering sorbent chamber 110 via a heat exchange mechanism or arrangement. In this way, effective cooling and condensation of water vapor output from the sorbent chamber 110 may be facilitated, and conversely, heating and drying of the gas leak 160 may be facilitated. Without being bound by any particular theory, the mixture of water vapor and fluid of gas blow-by drawn from the adsorbent material may create an elevated pressure within adsorbent chamber 110, causing the water vapor to rapidly change phase to liquid water, for example, upon moving the mixture to a higher pressure condition via vacuum pump 120.

Other methods and details for optimizing the production of liquid water are described in U.S. application No.16/657,935, filed on 18.10.2019, entitled "Systems and methods for generating liquid water using high efficiency technical solutions that optimize production".

In various embodiments, metabolic heat from the wearer of the wearable water generation device and latent heat of condensation carried by the air flow from the condenser may be exchanged with the adsorbent chamber and/or adsorbent material, further driving desorption kinetics. In addition to placing the sorbent at a reduced atmospheric (atmospheric) pressure, the sorbent material and sorbent chamber may also be configured to receive low-level heat from: (ii) ambient conditions, (ii) wearer's metabolism such as body contact or respiratory heat exchange, (iii) condensation heat extracted from the condenser for use as cogeneration heat, (iv) electrical waste heat extracted from any components in use, such as a vacuum pump, and (v) solar thermal energy. In various embodiments, the solar thermal energy utilized by the wearable water-generating device may be passive, rather than a direct consideration for the wearer to position himself for peak solar activity.

The open-loop thermodynamic cycles described herein may be implemented for wearable or portable water production based on control of depressurization conditions, sorbent chamber controlled gas leakage (blow-by), and/or time dynamics of depressurization conditions. Additionally, the nature of the sorbent material integrated in the wearable water-generating device and its physical configuration may be configured to absorb and conduct thermal energy from passive low-grade heat sources.

In various embodiments, the reduced pressure conditions can be formed within adsorbent chamber 110 such that the reduced pressure conditions increase the ratio of the vapor pressure of water captured by adsorbent material 112 or relative to adsorbent material 112 to the partial pressure of water vapor in adsorbent chamber 110. In some embodiments, the reduced pressure condition may be formed within adsorbent chamber 110 such that the reduced pressure condition increases the ratio of the vapor pressure of water captured by the adsorbent material to the total pressure in adsorbent chamber 110. The water vapour pressure or equilibrium vapour pressure of water is understood herein to mean the pressure which is applied at a given temperature when the water vapour is in thermodynamic equilibrium with its condensed phase in the adsorbent material or with respect to the adsorbent material. As used herein, the partial pressure of water vapor in the adsorbent chamber may be defined by the pressure exerted by water vapor in the gas mixture when occupying the adsorbent chamber alone, and the total pressure in the adsorbent chamber may be defined as the sum of the partial pressures of all gases in the mixture.

In various embodiments, the depressurization conditions can be dynamically or otherwise controlled or optimized by increasing the ratio of the pressure of the water vapor captured by the sorbent material to the partial pressure of water vapor in the sorbent chamber. In various embodiments, the reduced pressure conditions may be optimized by increasing the ratio of the pressure of the water vapor captured by the adsorbent material to the total pressure of the gas in the adsorbent chamber. In an exemplary control scheme, the depressurization conditions can be configured such that the water vapor pressure captured by the sorbent material remains above the water vapor partial pressure in the chamber volume.

Various methods may be employed to control and/or optimize the depressurization conditions within the adsorbent chamber so as to drive the water vapor trapped by the adsorbent material during the loading time to vapor pressure saturation during the release time. Since the adsorbent chamber volume is at a vacuum or negative pressure relative to ambient pressure, any passive heat or thermal energy source (e.g., body heat of the wearer) can be introduced into the adsorbent chamber volume to heat the adsorbent material. In some embodiments, the sorbent material may absorb waste heat generated by operation of one or more components of the wearable water generation device and/or its surroundings.

In various embodiments, the wearable water-generating device sorbent material may be passively loaded with atmospheric water, for example, according to a diurnal cycle. As another operational example, the water generator valve may be actuated in an alternating manner according to a diurnal cycle and/or operational set point to seal the device housing volume during a release time and open during a loading time.

In various embodiments, the wearable water generating device may include a controller (e.g., controller 104) to maximize production of liquid water at the condenser based on current or predicted environmental conditions (e.g., sunlight, ambient temperature, ambient humidity, etc.), current or predicted system properties (e.g., ambient and/or wearer temperature), etc.

In various embodiments, the wearable water-generating device 100 includes an auxiliary energy-generating and/or energy-storage component 106 (see fig. 3 and 4) configured to provide power to at least a portion of the wearable water-generating device 100 (e.g., a fan 130, a vacuum pump 120, valves, and/or the like). In some examples, wearable water generation device 100 includes a solar cell and/or battery configured to convert solar radiation to electricity to store power as electrochemical energy and provide power to wearable water generation device 100.

Further, the wearable water generation device 100 may use one or more sensors, onboard deterministic and/or machine learning algorithms, information about the thermodynamics of the water vapor, information about the properties of the sorbent material, information about the amount of liquid water produced, information about the amount of water vapor retained by the sorbent material to maximize water production at the condenser. In various embodiments, wearable water-generating device 100 may include such sensors; however, in various embodiments, wearable water generation device 100 may communicate with such sensors, but such sensors do not comprise a portion of wearable water generation device 100 itself. The wearable water-generating device may also include one or more indicators (e.g., lights, such as LEDs) that may be configured to provide information regarding the operation of the system. For example, in some embodiments, the indicator may be configured to provide information (e.g., visually, e.g., to the wearer) that the system is running, that maintenance is recommended, or that the component has failed and/or is failing, and/or the like. Any desired information, including the information described above with respect to the indicators, may be transmitted over the communication network (e.g., alone and/or in conjunction with operation of any of the indicators).

While the sorbent material may be used in wearable water generation devices that are implemented or operated under an open-loop thermodynamic cycle as described above, other embodiments or methods of operation employing the sorbent material described herein are also possible.

Wearable water generating device adsorbent material

Turning now to a description of the sorbent materials and characteristics, FIG. 5 depicts the enthalpy work and water mass absorption within the relative humidity range (i.e., 10-100% RH) for three representative categories of sorbent materials: conventional silica gel (Si-gel), metal Organic Framework (MOF), and Ionic Liquid (IL) as shown. As shown in fig. 5, MOFs showed high water uptake at mid-range RH; ionic liquids can maintain enthalpy work for efficient water generation over the entire RH range and/or under stringent operating requirements. In various embodiments, the sorbent material of the wearable water-generating device may be selected, defined and/or configured for high isothermal behavior within a relative humidity range of at least 10-100% or at least 2-100%RH.

Sorbent materials employed in wearable water generation devices can be selected and/or configured for various features, for example, kinetics provided by the high surface area of the graded (layered) porous desiccant, loading potential of inorganic salts, non-poisoning by other substances in the surrounding environment, high thermal conductivity, and/or stability under all cycling conditions. Further, the wearable water-generating device sorbent material can be selected and/or configured to have stable or high isothermal behavior over a relative humidity range of at least 10-100% rh or even 3-100% rh (e.g., as shown in fig. 5).

Ionic Liquids (IL) are a class of materials that can have tunable properties. Is counted as 10 ⁶ The organic ion pairs produce so-called low temperature ionic liquids. These systems can be tuned from hydrophilic to highly hydrophobic, on the order of viscosity, can be functionalized to perform various catalytic functions, and can be highly hygroscopic. Without being bound by any particular theory, the degree of hygroscopicity can be driven by charge screening on the ions of the ionic liquid. Furthermore, the ionic liquids may be directly tailored for their hardness/softness, details of the electronic structure of particular moieties, and hydrophobicity and/or shape of substituentsIsothermal line or isothermal behavior. As described herein, the degree to which a material can adsorb/absorb water vapor from the environment, as well as the enthalpy work on that water vapor under various relative humidity conditions, can affect water production. In various embodiments, the sorbent material may be selected for use in wearable water generating devices according to its isotherm behavior over a wide range of RH.

Various methods may be employed to synthesize an IL and/or SILER having a desired set of properties, for example, U.S. patent application Ser. No.13/096,851 entitled "Metal-air-temporal chemical liquid with liquid fuel" filed on 28.4.2011, U.S. patent application Ser. No.16/344,751 entitled "filed on 24.10.2017 and entitled" Solvent-less ionic liquid epoxy resin "filed on 18.2.2020 and International application Ser. No. PCT/US2020/018682 entitled" Solvent-less ionic liquid epoxy resin "filed on 18.2020.

While ILs enable all adjustability and phenomenological ranges, they are liquids and therefore may lack surface area to support interesting dynamics for deployment in wearable water generating devices. As described in further detail below, one class of polymeric materials may enable physicochemical engineering of the IL while providing mechanical properties of a highly crosslinked epoxy system that is suitable for deployment in wearable water generating devices. For purposes of facilitating the description herein, we refer to such materials as "SILER" or solventless ionic liquid epoxy resins.

Fig. 6 illustrates a simplified SILER polymerization according to various embodiments, where both components of the two-part epoxy system are ionic liquids. In this example, the substituent of R1+ may be referred to as a "hardener" chemical, and the ionic R2 "may have a glycidol substituent. The mixture of these two systems can yield zwitterionic polymers with adjustable free volume, taking into account the residual ionic liquid a- | B +. In various embodiments, R1 and R2 can also be anionic or cationic, resulting in an ionomer polymer. This simplified framework enables engineering of the final physicochemical, mechanical and physical properties of the final SILER polymer.

Fig. 7 (a) and 7 (b) show a non-limiting set of exemplary silicon IL groups that may be used in the wearable water-generating devices described herein. These SILER structures can have a wide range of substituents and provide a wide range of properties. In various embodiments, the groups R1, R2, R3, and R4 may be selected as any desired chemical chain. In various embodiments, Y may be a nucleophile, including but not limited to-NH 2, -SH, -OH, -SeH, -PH2, or other nucleophilic substituent, which may react with an epoxy group to form a stable chemical bond, as an example of a complete polymerization reaction to form a dimer. Furthermore, in various embodiments, Y and epoxy moieties may be exchanged between R1 and R2. In various embodiments, the anionic and/or cationic moieties can be any desired ionic substituent. In one non-limiting example, the resin and hardener may have different charges; however, in various embodiments, the resin and hardener comprise counterions of the same sign, which can provide a charge-binding polymer.

Two exemplary systems are shown in fig. 8 (a) and 8 (b), fig. 8 (a) depicting a tetraamino aromatic crosslinker with a bromine counterion, and fig. 8 (b) showing the diepoxide imidazolium dodecyl sulfate IL. When the two ionic liquids are mixed, they react to form an ionomer whose mechanical properties are similar to those of commercially available epoxy polymers, but with a large image quality (icoticity) and significant hygroscopicity.

In various embodiments, the wearable water-generating device can include a SILER-based ionic polymer system having an inherently formed regular porosity (e.g., mesoporosity) when a hardener compound and an epoxy compound are polymerized. Fig. 9 (a) and 9 (b) show the synthesized SILER polymer, and its pore structure on the meso and micro scales. In particular, fig. 9 (a) depicts an image of the porous SILER polymer so synthesized, and fig. 9 (b) shows a photomicrograph of the same SILER polymer.

Fig. 10 depicts a graph of an exemplary set of water vapor absorption isotherms (mass% water absorption in the% relative humidity range) for the following four exemplary SILER-based ionomer polymer systems for the sorbent material components: imidazolium bromide hardener (3 ImNHBr), linear triethylmethylammonium crosslinker (TriNH 2 Br) and two SILER polymers (10.

In various embodiments, the water uptake of the sorbent material can be adjusted by varying the range covered by the w/w% of the cross-linker, hardener, resin anion, and/or IL (w/w% inclusion). When the direction of the RH scan was reversed, there was no significant lag in the change in water absorption mass (Δ m/m 0) for all samples relative to the behavior of the RH plot, confirming the thermodynamic reversibility of the water absorption/desorption process.

As shown in fig. 10, the linear crosslinker and the imidazolium bromide hardener showed maximum water absorption of 127% and 90%, respectively. The polymer exhibits a resin anion dependent behavior. The polymer with the most hydrophobic anion (PF 6) had a maximum Δ m/m0 value (90% rh) of 27% (and not shown, the less hydrophobic (BF 4) polymer was nearly three times higher, 76% at the same relative humidity).

Furthermore, as shown in fig. 10, when additional ionic liquids (non-reactive) are included in the polymer composition, the overall hydrophilicity of the material can be altered. For example, the presence of 10% w/w of a more hydrophobic ionic liquid such as P4448Br and P4448Ibu can reduce the water absorption of BF4 polymer from 90% RH to 52-55% under the same conditions.

The sorbent material of the present system can comprise any desired media in any desired configuration (e.g., such that the hygroscopic material, desiccant, or sorbent media is capable of adsorbing and desorbing water). In some embodiments of the wearable water generating device, the hygroscopic or adsorbent material is capable of adsorbing at a first temperature and/or pressure and desorbing at a second temperature and/or pressure. The sorbent material may be provided as a liquid, a solid, and/or combinations thereof. The hygroscopic material may be provided as a porous solid impregnated with the hygroscopic material. For further examples, the sorbent material may include one or more materials selected from the group consisting of: ionic liquids, silica gel, alumina gel, montmorillonite clay, zeolites, molecular sieves, metal organic frameworks, activated carbon, metal oxides, lithium salts, calcium salts, potassium salts, sodium salts, magnesium salts, phosphates, organic salts, metal salts, glycerin, glycols, hydrophilic polymers, polyols, polypropylene fibers, cellulosic fibers, derivatives thereof, and combinations thereof. In some embodiments, the hygroscopic material may be selected and/or configured to avoid adsorbing certain molecules (e.g., those that may be toxic when consumed by a human).

There are several advantages to using a SILER-based sorbent material in a deployable, efficient wearable water-generating device. First, the absorption isotherm in a SILER material is an inherent property of chemistry; because adsorption is driven by charge screening of organic salts, it is a bulk property of the material and is a non-poisonable or otherwise retarded adsorption process, like mesoporous adsorption methods that rely on clean, molecularly stable surface properties. In addition, the free volume driven liquid-like transport kinetics combined with the ability to create highly cross-linked and stable hierarchical porous structures means that the absorption kinetics are fast. The fact that the SILER materials can be designed both synthetically to achieve thermodynamics and by engineering to achieve interesting kinetics makes them suitable for wearable water-generating device devices. In various embodiments, the use of a SILER material is associated with the open loop thermodynamic cycle described herein, resulting in an efficient wearable water generating device.

The present disclosure further provides a method or process for operating a wearable water generating device to generate liquid water from air. In various embodiments, the wearable water generating device 100 includes a controller 104, the controller 104 configured to control the wearable water generating device 100 to maximize production of liquid water from the condenser 140. In various embodiments, controller 104 maximizes the production of liquid water by adjusting the partial pressure of water vapor on or above sorbent material 112 within sorbent chamber 110 relative to reduced pressure conditions (e.g., caused by vacuum pump 120).

In various embodiments, a method for operating wearable water generating device 100 includes creating a reduced pressure condition by maintaining a pressure in adsorbent chamber 110 below atmospheric pressure surrounding adsorbent chamber 110 such that water vapor captured by adsorbent material 112 during loading operations is near vapor pressure saturation. In various embodiments, the reduced pressure condition is created within adsorbent chamber 110 such that the reduced pressure condition increases the ratio of the vapor pressure of water captured by adsorbent material 112 or relative to adsorbent material 112 to the partial pressure of water vapor in the interior volume of adsorbent chamber 110. In various embodiments, a reduced pressure condition is created within the interior volume of adsorbent chamber 110 such that the reduced pressure condition increases the ratio of the vapor pressure of water captured by adsorbent material 112 to the total pressure in the interior volume of adsorbent chamber 110. In various embodiments, reduced pressure conditions are pressures less than about 0.8atm, about 0.7atm, or about 0.6atm (where "about" means +/-0.05 atm). In various embodiments, reduced pressure conditions are pressures less than about 0.5atm (where "about" means +/-0.05 atm). Further, in some embodiments, the reduced pressure conditions are between 0.1 and 0.8 atm.

As understood herein, the water vapor pressure or equilibrium vapor pressure of water is the pressure applied at a given temperature when water vapor is in thermodynamic equilibrium with its condensed phase located in the hygroscopic or adsorbent material or with respect to the hygroscopic or adsorbent material. As understood herein, the partial pressure of water vapor in the adsorbent chamber is the pressure that the water vapor in the gas mixture would exert if it occupied the adsorbent chamber alone. As understood herein, the total pressure in the interior volume of the adsorbent chamber is the sum of the partial pressures of all gases in the mixture.

Fig. 11 illustrates a flow diagram of an exemplary method 200 of producing liquid water from a process gas (e.g., ambient air), according to certain embodiments. The method 200 is merely exemplary and is not limited to the embodiments presented herein. The method 200 may be used in many different embodiments or examples not specifically depicted or described herein. In some embodiments, the actions of method 200 are performed in the order presented. In other embodiments, the actions of method 200 may be performed in any other suitable order. In other embodiments, one or more of the acts in method 200 may be combined, skipped, or omitted. In many embodiments, the method 200 may be performed with a device and/or system similar to or the same as the wearable water-generating device 100 of fig. 3, 4, or derivatives thereof.

In various embodiments, method 200 includes an operation or act 210 of providing a wearable water generating device comprising an adsorbent chamber and an adsorbent material held within the adsorbent chamber, and a condenser operably coupled to an interior volume of the adsorbent chamber. In some embodiments, the system is similar to or the same as the wearable water-generating device 100 of fig. 3 or 4.

In various embodiments, method 200 includes an act 220 of inputting a process gas (e.g., ambient air) into the sorbent chamber (i.e., for absorbing water by the sorbent material) during a loading time or cycle. In various embodiments, method 200 includes an act 230 of exposing the sorbent chamber to a source of thermal energy (e.g., low-grade bulk heat) during a release time or cycle (i.e., for desorbing water from the sorbent material). In various embodiments, method 200 further comprises an act 240 of creating a reduced pressure condition within the adsorbent chamber during the release time or cycle (i.e., for desorbing water from the adsorbent material). In various embodiments, method 200 includes an act 250 of outputting water vapor from the sorbent chamber to a condenser during a release time. In various embodiments, the method 200 includes repeating any one or more steps of the method 200 until a desired volume of liquid water is reached.

Various methods for operating the wearable water-generating device 100 during release of water vapor into the sorbent chamber include maintaining the pressure within the sorbent chamber at a pressure that is lower than the atmospheric water vapor pressure to which the sorbent material is exposed during the loading time. In various embodiments, method 200 includes an act 240 that includes activating a pump to evacuate the sorbent chamber to a pressure at or below atmospheric pressure. In various embodiments, method 200 may further comprise the act of introducing a carrier gas leak (e.g., 160) into sorbent chamber 110 during the release time. For example, in some embodiments, carrier gas from the atmosphere (e.g., via an inlet at 160) or elsewhere is input into sorbent chamber 110 during the release time when the interior volume of sorbent chamber 110 is at a negative pressure (e.g., relative to atmospheric pressure). Without wishing to be bound by any particular theory, the water vapor and leakage (blow-by) carrier gas mixture drawn in by the hygroscopic material may create an elevated total pressure within the adsorbent chamber 110 and/or within the condenser 140. Once the mixture is moved to a high pressure condition via vacuum pump 120, for example to condenser (condenser) 140, the elevated total pressure may cause a phase change of water vapor to liquid water.

In various embodiments, the method for operating the water generation apparatus 100 includes adjusting the reduced pressure conditions by adjusting the pump speed (e.g., adjusting the vacuum pump 120 via the controller 104) and/or adjusting the flow rate of the carrier gas into the sorbent chamber 110 (e.g., via 160 controlled by the controller 104) to continuously drive the efficient release and capture of water vapor from the sorbent material 112. In various embodiments, creating, optimizing, and/or adjusting the reduced pressure conditions within adsorbent chamber 110 includes controlling the pump speed to increase the ratio of the partial pressure of water vapor on or above adsorbent material 112 to the partial pressure of water vapor set in the gas in adsorbent chamber 110. Such an increased rate may increase the water vapor output from sorbent chamber 110 during the release time. In various embodiments, the water generation apparatus 100 is configured to increase the efficiency of liquid water production at the condenser 140 by adjusting the reduced pressure conditions within the adsorbent chamber 110, for example, by determining or adjusting the rate of carrier gas leaking or input into the interior volume of the adsorbent chamber 110 (e.g., via the inlet 160).

In one example, a method for operating wearable water-generating device 100 includes adjusting a reduced-pressure condition by determining (e.g., by a device controller) that a body heat, temperature, or metabolic rate of a wearer has increased above a predetermined threshold, and in response, reducing an amount of energy (e.g., from an on-board device battery) directed to a pumping device to reduce pressure within a sorbent chamber. In another example, a method for operating wearable water-generating device 100 includes determining (e.g., by a controller) that a body heat, temperature, or metabolic rate of a wearer has decreased below a predetermined threshold, and in response, activating a pumping device to decrease a pressure within a sorbent chamber. In yet another example, a method for operating wearable water generating device 100 includes determining (e.g., by a device controller) an amount (amount) or quantity (quality) of water retained by a sorbent material (e.g., via a conservation calculation of desorption-absorption mass based on known sorbent material properties and pressure and/or temperature), and in response, determining a sorbent chamber pressure setpoint (e.g., decreasing chamber pressure in response to a decrease in body heat or temperature, increasing chamber pressure in response to an increase in body heat or temperature, etc.).

The above specification and examples provide a complete description of the structure and use of exemplary embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. Therefore, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiments. For example, elements (components) may be omitted or combined into a single structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions and addressing the same or different issues. Similarly, it is to be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments.

The claims are not intended to be inclusive and should not be construed to include device + functional limitations or step + functional limitations unless the phrase "device is used for" or "step is used for" in a given claim, respectively.

Claims

1. A wearable water generating device, comprising:

a sorbent chamber comprising a sorbent material to capture water vapor from ambient air during a loading cycle, the sorbent material configured to absorb thermal energy;

a vacuum pump configured to create a reduced pressure condition within the adsorbent chamber, thereby desorbing water from the adsorbent material during a release cycle, wherein the reduced pressure condition increases a ratio of a vapor pressure of water captured by the adsorbent material to a partial pressure of water vapor in the adsorbent chamber; and

a condenser for generating liquid water from the desorbed water vapor received from the vacuum pump.

2. The wearable water generating device of claim 1, wherein the sorbent material is configured to absorb thermal energy from a wearer of the atmospheric water generating device.

3. The wearable water generating device of claim 1, wherein the sorbent material is configured to absorb thermal energy from solar radiation impinging on the atmospheric water generating device.

4. The wearable water generating apparatus of claim 1, further comprising a fan configured to cool the condenser.

5. The wearable water generating apparatus of claim 1, wherein the vacuum pump discharges the desorbed water vapor as steam at atmospheric pressure.

6. The wearable water generating device of claim 1, wherein the vacuum pump exhausts the desorbed water vapor to a pressure higher than atmospheric pressure.

7. The wearable water generating device of claim 6, further comprising a compressor in combination with a vacuum pump, and the desorbed water vapor is vented from the adsorbent chamber to a pressure greater than atmospheric pressure.

8. The wearable water generating device of claim 1, further configured to operate in an open loop thermodynamic cycle.

9. The wearable water generating apparatus of claim 1, wherein an outlet of the vacuum pump is configured to exchange heat from water vapor discharged therefrom to the adsorbent chamber, thereby increasing at least one of a rate and a vapor pressure of water vapor desorbed from the adsorbent material.

10. The wearable water generating device of claim 1, wherein the adsorbent material comprises an ionic liquid.

11. The wearable water generating device of claim 1, wherein the adsorbent material comprises a solvent-free ionic liquid epoxy.

12. The wearable water generating device of claim 1, wherein the sorbent material comprises an ionic liquid entrained into a porous solid.

13. The wearable water generating device of claim 1, wherein the adsorbent material comprises a metal-organic framework.

14. The wearable water generating apparatus of claim 1, further configured to exchange heat from the vacuum pump to the sorbent material.

15. The wearable water generating device of claim 1, further configured to exchange heat from the condenser to the sorbent material such that a power requirement of the vacuum pump is reduced, thereby increasing the coefficient of performance.

16. The wearable water generating apparatus of claim 1, wherein the sorbent chamber comprises an inlet for input of gas leak during a release cycle.

17. The wearable water generating device of claim 16, wherein the carrier gas leak comprises ambient air.

18. The wearable water generating apparatus of claim 1, further comprising:

one or more sensors; and

a controller coupled to the one or more sensors and the vacuum pump, the controller configured to maximize water production in the condenser by adjusting a reduced pressure condition during a release time.

19. The wearable water generating device of claim 1, further comprising a controller configured to maximize water production rate of the condenser by maintaining a reduced pressure condition in the sorbent chamber below a predetermined set point.

20. The wearable water generating device of claim 19, wherein the controller maintains the reduced pressure condition in the sorbent chamber below a predetermined set point by adjusting power input to the vacuum pump.

21. The wearable water generating apparatus of claim 19, wherein the controller is further configured to adjust a flow rate of the gas leak to maintain a reduced pressure condition in the sorbent chamber.

22. A method for operating a wearable water generating device, the method comprising:

capturing water vapor from ambient air by a sorbent material in a sorbent chamber during a loading cycle;

creating a reduced pressure condition in the adsorbent chamber during the release cycle;

desorbing water from the adsorbent material during a release cycle; and

the water vapor output from the adsorbent chamber is condensed to liquid water during the release cycle.

23. The method of claim 22, wherein the loading cycle and the release cycle operate in an open loop thermodynamic cycle.

24. The method of claim 22, further comprising inputting the gas leak into the sorbent chamber during a release cycle.

25. The method of claim 22, wherein capturing water vapor comprises inputting ambient air into an adsorbent chamber of the wearable water-generating device.

26. The method of claim 22, wherein desorbing water from the sorbent material during a desorption cycle comprises exposing the sorbent material to a low grade heat source.

27. The method of claim 26, wherein the low grade heat source comprises heat energy from a wearer of the atmospheric water generating device.

28. The method of claim 26, wherein the low-grade heat source comprises passive ambient heat, solar energy, or a combination thereof.

29. The method of claim 22, wherein creating reduced pressure conditions comprises adjusting the reduced pressure conditions by adjusting a vacuum pump rate.

30. The method of claim 22, wherein creating the reduced pressure condition comprises adjusting the reduced pressure condition by adjusting a flow rate of the carrier gas into the adsorbent chamber.

31. The method of claim 22, wherein the method further comprises: determining a physical condition of the wearer; and adjusting the reduced pressure condition based on the determined physical condition.

32. The method of claim 31, wherein the wearer's physical condition is the wearer's body heat, temperature, metabolic rate, or a combination thereof.

33. The method of claim 31, wherein the method includes determining that the wearer's physical condition has increased above a predetermined threshold, and reducing the amount of energy input to create the reduced pressure condition based on the determined wearer's physical condition.

34. The method of claim 22, wherein the method comprises: determining that the physical condition of the wearer has decreased below a predetermined threshold; reducing the pressure within the adsorbent chamber based on the determined physical condition of the wearer.

35. The method of claim 22, wherein the method further comprises: determining an amount of water in the sorbent material; and in response, determining a sorbent chamber pressure set point based on the determined amount of water.